Ligand development

In general, of the mixed phosphorus-thioether ligands that have been used in the asymmetric hydrogenation of prochiral olefins, the thioether-phosphinite ligands have provided some of the best results. As an example, a new class of thioether-phosphinite ligands developed by Evans et al. has recently proved to be very efficient for the rhodium-catalysed asymmetric hydrogenation of a... 

The trap (trans-chelating phosphines) ligands developed by Ito and co-workers [33] form nine-membered metallocycles where trans-chelation is possible. However, it is not clear whether the cis isomer which has been shown to be present in small amounts or the major trans isomer is responsible for the catalytic activ-... 

Figure 3. C2-Symmetric P,P- and A/,A/-ligands developed specifically for allylic substitution.

The range of ligands developed for ionic liquid catalysis is much smaller than that for other immobilization solvents such as water and fluorous phases as off the shelf ligands and catalysts can often be used in ionic liquids. For example, a number of catalysts that were developed to operate in organic solvents under homogeneous conditions are salts themselves and do not need to be modified for use in ionic liquids [25],... 

Figure 7.9. Lim ligands developed by Sasol position of R group not defined...

For intermolecular cyclopropanations with unsubstituted diazoacetates the highest asymmetric inductions can be achieved with the copper(I) complexes of C2-symmetric, bidentate ligands developed by Pfaltz (e.g. 1) and Evans (2). The chiral rhodium(II) complexes known today do not generally lead to such high enantiomeric excesses as copper complexes in intermolecular cyclopropanations. For intramolecular cyclopropanations, however, chiral rhodium(II) complexes are usually superior to enantiomerically pure copper complexes [1374]. 

Fig. 8.5. Binaphthol-derived phosphoramidite ligands developed by Feringa et al.

Application of PSSC for de novo ligand development for the protein cluster Cdc25A phosphatase-acetylcholinesterase-1 ip-hydroxysteroid dehydrogenase... 

When we first ventured into the field of [2.2]paracyclophane ligand synthesis, successful applications of such ligands were relatively rare [2]. The most prominent example was clearly the PHANEPHOS ligand developed by Rossen and Pye [3], who have found several successful applications in asymmetric hydrogenation reactions. A comprehensive survey of [2.2]paracyclophane-based ligands can be found in recent reviews [4, 5]. 

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